public class Solution1 {

    //
    public boolean isValidSudoku(char[][] board) {
        boolean[][] row = new boolean[9][10];
        boolean[][] col = new boolean[9][10];
        boolean[][][] grid = new boolean[3][3][10];

        for(int i = 0; i < 9; i++){
            for(int j = 0; j < 9; j++){
                if(board[i][j] != '.'){
                    int tmp = board[i][j] - '0';
                    if(row[i][tmp] || col[j][tmp] || grid[i / 3][j / 3][tmp]){
                        return false;
                    }
                    row[i][tmp] = col[j][tmp] = grid[i / 3][j / 3][tmp]  = true;
                }
            }
        }
        return true;
    }

    //
}
